How does it work? Whirlwind with 'blood funnel' rune heals 1% of max health per each critical hit that lands (afaik there is no penalty for it, unlike for life on hit or external life leech, which don't regen listed hp, it depends on skill (each has individual penalty), or difficulty (80% penalty for inferno life leech). So that 1% is not that low, given how often whirlwind hits.
To keep on whirling, we need fury generation, lots of it, there comes battle rage rune 'into the fray', which grants 15 fury per crit. With just a couple of enemies it provides unlimited whirlwind (even vs single target we can whirl much longer).
Another bonus is frenzy with maniac, we get 20% damage with fully charged frenzy, and we can just land one frenzy hit every couple of seconds, to sustain that bonus (that boosts our all attacks, including whirlwind). Frnzy also generates fury if we fight vs single target, and is our main skill then.
Revenge is not used as main healer here, 'best served cold' rune, grants 10% crit chance for 12s, which is ideal for this build. We still have tha panic healing button, but rather use this for crit bonus. Even if you have revenge ready to use, hold it, till 12s crit bonus timer is almost finished, then use it. More crit, means more healing via ww blood funnel.
Now last part, wrath of the berserker with 'thrive on chaos' rune. Unlike most barb, who pick insanity rune (100% damage bonus for 15s) i find it not that great. Main problem is, monsters in later inferno acts have so much health, we are unable to kill them within 15s of insanity duration. And then we lose all wotb bonuses (dodge, speed, crit), but not just that, the most important, unlisted bonus - immunity to crowd control effects, while under berserk form. It makes us impossible to freeze, teleport, lock by jail monster, and fear doesn't work against us. It makes battles a lot easier, against most annoying combos of elite traits. The idea is, to increase duration of berserker, through entire battle. This skill is nearly impossible to sustain during normal play, because we can't charge it up, we can only turn back duration while fighting. If there are big gaps between monsters on map, we will lose the bonus. But if we fight elite pack, we can sustain wotb, as we have targets to hit. Whirlwind is great fury sink (16 per spin), and we regen huge amounts of fury, via critical hits. That really works with 'thrive on chaos' rune, we need just 2-3 enemies, with more crit gear later on, it can probably work even vs single target.
As for passive, you can switch to mastery, use it with axe for 10 more crits (I have sword on barb so decided to use ruthless). Two defensive passives, later with better armors, we can probably exchange one with weapon mastery/ruthless if we get enough defense (if there is such thing).

On a side note, you need decent gear for this barb to work, pretty much same as "boring" revenge tank builds, and some more crit chance on it, so it is even more expensive. But it as result we get faster, and better character, and most importantly more interesting to play, we can use classic barbarian trademark skill - whirlwind.
it has also tons of room for improvements, more critical chance we collect, the better it works, mainly heals us faster.